I m not sure about rpi3 now after the previous post...it s definittly working with pi 2Sent from my SM-T280 using Tapatalk
I got mixed up. The two Pi's I've been testing this on are both 2b's. I own a 3b but it has not been a part of my testing and troubleshooting of this issue. Apologies for any confusion.
I think my CEC issue may just be a slightly different CEC bug from what you many of you have experienced. A different CEC bug altogether introduced in LibreElec 8/Kodi 17 that is specific to my LG TV in the living room.